1. Field of the Invention
The present invention relates to a door lock, and more particularly to a door lock that has a simplified structure and can be operated smoothly.
2. Description of the Prior Art
A conventional door lock in accordance with the prior art has an outside doorknob, an inside doorknob and a latch button. The outside doorknob is mounted on an outside of a door mounted in a doorway to a room. The inside doorknob is mounted on an inside of the door. The latch button is mounted in the inside doorknob. A person in the room can move the latch button to selectively lock or unlock the door lock.
When the latch button is in a default position, a person can turn the outside doorknob or the inside doorknob to unlock the door lock and open the door. When the latch button is in a locking position, a person outside the room is unable to turn the outside doorknob. A person in the room has to return the latch button to the default position to unlock the door lock before being able to turn the inside doorknob to open the door.
However, a child may not know the latch button must be in the default position before turning the inside doorknob to open the door. Therefore, in an emergency situation, a fire, an earthquake or the like, the child may use excessive time escaping from the room by not being able to operate the door lock.
An improved door lock in accordance with the prior art is developed to overcome the aforementioned problems of the conventional door lock. The improved door lock has an inside doorknob and a latch button. A person can turn the inside doorknob to simultaneously rotate the latch button from a locking position to a default position. So, a person can directly turn the inside doorknob to unlock the door lock and simultaneously open a door on which the improved door lock is mounted, without returning the latch button back to the default position.
However, compared to the conventional door lock, the improved door lock has more elements and is more structurally complex, preventing smooth operation and increasing costs of manufacturing.